1. The Cell Cycle and Cancer The Cell Cycle Cytokinesis 1 2 3

2. The Cell Cycle and Cancer The Cell Cycle One key to advanced life is cell division. Cells divide millions of times every day to sustain the life and growth of a single human. This process is called the Cell Cycle. Cytokinesis 1 2 3

3. There are several factors that regulate the cell cycle and assure a cell divides correctly. 1.Before a cell divides, the DNA is checked to make sure it has replicated correctly. If DNA does not copy itself correctly, a gene mutation occurs. 2.Chemical Signals tell a cell when to start and stop dividing. 3.Neighboring cells communicate with dividing cells to regulate their growth also.

4. Out-of-control cell division caused by DNA mutations can fuel cancer. Cancer is a disease of the cell cycle. Some of the body’s cells divide uncontrollably and tumors form Tumors in LiverTumor in Colon

5. DNA mutations disrupt the cell cycle. Mutations may be caused by: 1. radiation 2. smoking 3. Pollutants 4. chemicals 5. viruses

6. While normal cells will stop dividing if there is a mutation in the DNA (and even die), cancer cells will continue to divide with mutation.

7. Due to DNA mutations, cancer cells ignore the chemical signals that start and stop the cell cycle. This prevents cancer cells from communicating with neighboring cells. Cells continue to grow and form tumors. Skin cancer Developing tumor

8. SUMMARY Normal Cell Division 1.DNA is replicated properly. 2. Chemical signals start and stop the cell cycle. 3. Cells communicate with each other so they don’t divide excessively and become overcrowded. Cancer Cells 1.Mutations occur in the DNA when it is replicated. 2. Chemical signals that start and stop the cell cycle are ignored. 3. Cells do not communicate with each other and tumors form.

9. Treating Cancers Cancer treatments include drugs that can stop cancer cells from dividing. Now scientists have for the first time reversed the process of cell division, a breakthrough that could eventually lead to treatments for cancer and other disorders.